Vehicle condition responsive monitoring system having priority indication

ABSTRACT

Apparatus for providing information as to plurality of conditions using a single air core gauge. Each condition being monitored controls a switch that in turn controls the energization of at least one winding, the magnetic fields generated by the windings forming a resultant magnetic field that controls the orientation of an indicia-bearing rotatable disc. When one or more windings are energized a lamp illuminates the indicia which the disc locates at a certain position so as to indicate the status of the condition which caused energization of the winding. The apparatus also gives priority to information on conditions which are of greater importance than other conditions also being monitored.

United States Patent Fales [151' 3,665,383 [451 May 23, 1972 [54]VEHICLE CONDITION RESPONSIVE MONITORING SYSTEM HAVING PRIORITYINDICATION Douglas I. Fales, Flint, Mich.

General Motors Corporation, Detroit, Mich.

Filed: Nov. 20, 1970 Appl. No.: 91,490

[72] Inventor:

[73] Assignee:

U.S. Cl ..340/52 I", 340/] 81 Int. Cl. ..G08b 19/00 FleldolSearch..340/52, 52 F, 177, 18], 195,

[56] References Cited UNITED STATES PATENTS 3,283,314 11/1966 Stewart..340/l77 X 3,302,l9l 1/1967 Ziegler ..340/l77 Primary Examiner-Alvinl-l. Waring Attorney-J. L. Carpenter and Paul Fitzpatrick ABSTRACTApparatus for providing information as to plurality of conditions usinga single air core gauge. Each condition being monitored controls aswitch that in turn controls the energization of at least one winding,the magnetic fields generated by the windings forming a resultantmagnetic field that controls the orientation of an indicia-bearingrotatable disc. When one or more windings are energized a lampilluminates the indicia which the disc locates at a certain position soas to indicate the status of the condition which caused energization ofthe winding. The apparatus also gives priority to information onconditions which are of greater importance than other conditions alsobeing monitored.

3 Claims, 6 Drawing Figures Patented May 23, 1972 2 Sheets-Sheet l A TTORNE Y Patented May 23, 1972 3,665,383

2 Sheets-Sheet 2 INVENTOR.

ou /as Z JZ/as A TTORNE Y VEHICLE CONDITION RILSPONSIVE MONITORINGSYSTEM HAVING PRIORITY INDICATION This invention relates to apparatuswhich advises as to the status of a plurality of conditions at variousremote locations and, more particularly, to motor vehicle systems formonitoring a plurality of conditions at various remote locations in amotor vehicle and for indicating the status of the conditions beingmonitored. This invention also relates to my copending applications Ser.Nos. 91,491 and 91,393 which were filed on Nov. 20, 1970, and assignedto the assignee of this invention.

Many warning systems for advising of conditions in a motor vehicle arepresently in widespread use. These systems may, for example, be employedto monitor fuel level in a gas tank, coolant level in a radiator, oilpressure in an engine crankcase, or the charging of a battery by anelectrical generating system. Generally these prior systems are of twotypes: they either provide a continuous indication of the conditionbeing monitored, the well-known fuel gauge being one example, or theyadvise the vehicle occupant only of a condition which has changed tosuch an extent as to need his attention, as is the case with lamps whichare employed as telltales. In either event, these systems have had tocompete for space with many other devices which must also be located ina vehicle dashboard so as to be within reach and observation of thevehicle operator. Since the motoring public is provided an opportunityto enjoy an ever-increasing number of comfort and convenience featuresoffered by vehicle manufacturers, the space limitations in vehicledashboards are continuously becoming more acute.

Accordingly, it is an object of this invention to provide apparatuswhich monitors a large number of conditions in a motor vehicle and whichemploys a single dashboard unit to convey information regarding thevarious monitored conditions to the vehicle operator.

A further object of this invention is the implementation of a single aircore gauge to monitor a plurality of conditions at various locations ina motor vehicle.

Another object of this invention is the provision of an air core gaugewhich indicates a plurality of conditions in a motor vehicle and whichonly provides an affirmative indication as to the status of themonitored conditions which the attention of the vehicle operator to oneor more of the conditions is required.

It is yet another object of this invention to provide apparatus formonitoring a plurality of conditions in a vehicle and which advises avehicle operator of the most urgent condition regardless of otherconditions being monitored that may also require his attention.

The satisfaction of the foregoing objects and the advantages of thesubject invention will be apparent from the accompanying description anddrawings, in which:

FIG. 1 depicts an air core gauge of the prior art which may be employedin practicing the subject invention.

FIG. 2 is a perspective view, with parts broken away, of an indicatorembodying the principles of the subject invention.

FIG. 3 is a cross-sectional view of the indicator in FIG. 1.

FIG. 4 is a schematic representation of an indicator circuit accordingto the principles of the subject invention.

FIG. 5 is a modification of the indicator circuit in FIG. 4 havingprovision for a single priority condition.

FIG. 6 is a modification of the indicator circuit in FIG. 5 havingprovision for a multiplicity of priority conditions.

Referring now to the drawings, FIG. 1 shows an air core gauge 10 of thetype disclosed in Ziegler, US. Pat. No. 3,302,191, which may be employedin practicing the subject invention. As shown in FIG. 1, the gauge 10includes a wind ing support member 12 on which are disposed fust andsecond coils l4 and 16. The first coil 14 includes a first set ofcoaxial windings 18 and and the second coil includes a second set ofcoaxial windings 19 and 21, the windings 18 through 20 in the coils 14and 16 being positioned and wound so as to generate magnetic fields whenenergized that oppose each other. The winding support member 12 supportsthe coils l4 and 16 so that their respective axes are substantially at90 degrees to each other, which causes the magnetic fields produced bythe 18 through 21 to combine in a resultant magnetic field in which themagnetic fields of the opposed windings are cancelled when the opposedwinding are equally energized. In addition, the gauge 10 also includes apermanent magnet amtature 22 rotatably supported by a shaft 24 that isrestrained in a guideway 26.

As shown in FIGS. 2 and 3, an indicator 28 according to the preferredand illustrated embodiment includes the gauge 10 of FIG. 1 disposed withthe shaft 24 vertical and drivably connected to a rotatable disc 30,which has a depending edge 32, so as to rotate the disc 30 in accordancewith the energization of the windings 18 through 21. A plurality ofwindows 34 through 37 which bear indicia are disposed in the dependingedge 32 of the disc 30 so as to be aligned with a light source, such asa lamp 38, that is mounted in a shroud 40 behind the depending edge 32of the disc 30. The lamp 38 and the winding support member 12 are heldin a fixed relative position by suitable supporting apparatus, such as abracket 42 illustrated in FIG. 3.

Accordingly, as a condition which is being monitored effects a change inthe energization of the windings 18 through a 21 the correspondingchange in the resultant magnetic field causes the armature 22 to rotateto a new position in which one of the windows 34 through 37 and theindicia which it bears is aligned with the lamp 38. Upon energization ofthe lamp 38 the window is illuminated by the lamp 38 and the vehicleoccupant is made aware of the change in the condition being monitored.

For example, if it is assumed that the lamp 38 and the windings 18through 21 are all normally de-energized and that one of the windings 18through 21 is responsive to the temperature of the vehicle engine, thelamp 38 is normally deenergized and the vehicle operator is thereforenot affirmatively advised of any malfunction of the conditions beingmonitored in the vehicle. That is, so long as the lamp 38 remainsde-energized he may assume that the conditions being monitored arefunctioning normally. However, should the engine temperature exceed apredetermined level the winding with which it is associated will beimmediately energized and at a predetermined time after the winding isenergized the lamp 38 will be energized, as will subsequently beexplained. Accordingly, the disc 30 is first rotated so as to align thewindow 36, on which is the indicia HOT, with the lamp 38 and then thelamp 38 is energized. Upon energization of the lamp 38 the vehicleoperator is advised of the overheated condition of the engine.

A control circuit 44 for controlling the energization of the windings 18through 21 and the lamp 38 is schematically illustrated in FIG. 4. Asshown in FIG. 4, several detection networks 46 through 49 are providedfor monitoring various conditions in a vehicle. Each detection network46 through 49 includes one of a plurality of normally open switches 50through 53 connected in series with one of the respective windings 18through 21. Power is supplied to the windings 18 through 21 by asuitable power source, such as a vehicle battery 54, through a powerswitch, such as a vehicle ignition switch 56, in accordance with thesetting of the switches 50 through 53. A resistor 58 is connected inseries with the windings 18 through 21 and the battery 54 so as to forma voltage divider in which the common junction 60 of the windings 18through 21 undergoes a wide voltage excursion in accordance with theenergization of the windings 18 through 21, the voltage excursion beingsensed by a PNP transistor 62 which controls the energization of thelamp 38.

So long as all the switches 50 through 53 are open, substantially theentire voltage of the battery 54 is applied through the ignition switch56 and the resistor 58 to the common junction 60 of the windingsl8through 21. Accordingly, the base 64 of the transistor 62, which isconnected to the junction 60, is at substantially the same voltage asthe emitter 66 of the transistor 62 so the transistor 62 is biased toits non-conductive condition. The transistor 62 thus normally preventsenergization of the lamp 38, which is in series with the collector 68 ofthe transistor 62.

the base 64 of the transistor 62 would thus be at a much lower voltagethan the emitter 66 and the forward biased baseemitter junction of thetransistor 62 makes the transistor 62 conductive so as to energize thelamp 38. Accordingly, the energization of the winding 20 causes the disc30 to be rotated so as to align the window 36 with the lamp 38 and theener-' gization of the lamp 38 illuminates both the window 36 and theindicia which it contains so as to advise the vehicle operator that theoverheated engine needs his attention.

It should be noted that the time constant formed by the resistor 58 andone of the windings 18 through 21 when the corresponding switch of theswitches 50 through 53 is closed provides a valuable time delay in theoperation of the indicator 28. Since the disc 30 in all probability isnot aligned with the lamp 38 for a proper indication the moment one ofthe switches 50 through 53 is closed, the disc 30 begins to rotate assoon as one of the windings 18 through 21 is energized. If the lamp 38also were immediately energized when one of the windings 18 through 21becomes energized the indicator 28 may give an initial indication thatis erroneous due to the motion of the disc 30. Accordingly, the windings18 through 21 and the resistor 58 are selected so that the voltage atthe junc- .tion'60 is decreased at a sufficiently slow rate when one ofthe switches 50 through 53 is closed as to introduce a certain timedelay into the control circuit 44.

By properly selecting the windings 18 through 21 and the resistor 58'the junction 60 voltage is maintained at a suffi- I ciently high voltageas to maintain the transistor 62 nonconductive until an energizedwinding has aligned the disc 30 for a proper indication of themalfunction. The disc 30 is thus always properly aligned before the lamp38 is energized. As persons versed in the art will appreciate, variousother time delay circuitry could also be employed to further delay theenergization of the lamp 38 after closure of one of the switches 50through 53. Indeed, the lamp 38 may be selected to be of a type in whichthe lamp is not illuminated for a certain time after the lamp isenergized. A slow lamp, as these lamps are sometimes called, wouldpreclude false indications by the indicator 28 before the disc 30 isproperly aligned and would therefore eliminate the need for additionaltime delay apparatus.

In the embodiment illustrated in FIG. 5, the control circuit 44 of FIG.4 has been modified to provide a priority of signals in accordance withthe importance which the vehicle operator attaches to the variousconditions being monitored. Since it is most likely that only a singlemalfunction, if any, will ever occur in a vehicle at a given time theembodiments previously discussed, which operate properly only inresponse to closure of a single switch, are nonnally quite satisfactory.However, if the vehicle operator attaches great importance to a certaincondition it is important that he be advised of changes in thatcondition regardless of simultaneous but less urgent malfunctions whichmay be present in the vehicle.

To this end transistors 70 through 72 have been inserted in thedetection networks 46, 47, and 49 in FIG. to render nonconductive thedetection networks 46, 47, and 49 when the switch 52 is closed inresponse to a malfunction of utmost urgency, such as low oil pressure inthe vehicle engine. Suitable bias resistors 74 through 76 connect thebases of the respective transistors 70 through 72 to the switch 52 sothat when the switch 52 is closed in response to low oil pressure in thevehicle engine the bases of the transistors 70 through 72 are placed atground potential. Since closure of one of the other switches 50, 51, or53 merely grounds the emitter of the corresponding transistors 70through 72 it is impossible for the transistors 70 through 72 to beconductive if the switch 52 is closed. Closure of the switch 52 thuseffects energization of the winding and the lamp 38 in the fashionpreviously described and also prevents energization of any of the otherwindings 18, 19, or 21 regardless of whether any of the switches 50, 51,or 53 are closed.

For example, if the switch 51 is closed due to a malfunction in thecondition which it monitors, such as thevehicle's electrical generatingsystem, the vehicle could still be operated for a short distance as thebattery will temporarily meet the vehicles electrical energyrequirements. Though the vehicle will continue operating the vehicleoperator will be advised of .the malfunction in the electricalgenerating system because closure of the switch 51 grounds the emitterof the transistor 71 while the base of the transistor 71 is at amuchhigher potential due to the leakage of a small current through thewinding 20 and the resistor 75. The base-emitter junction of thetransistor 71 is thus forward biased so as to render the transistor 71conductive and energize the winding 19. Since the current through thewinding 20 and the base of the .transistor 71 is very small the winding20 remains substantially deenergized and the entire resultant magneticfield which is generated is due to the energization of the winding 19.The disc 30 will thus be rotated and the lamp 38 will be energized so asto indicate the vehicle operator the malfunction in the electricalgenerating system in the fashion previously described.

However, upon closure of the switch 52 due to low oil pressure in theengine the vehicle operator should stop the engine immediately toprevent its being damaged. Accordingly, closure of the switch 52 groundsthe winding 20 and the base of the transistor 71 so as to energize thewinding 20 and switch ofl the transistor 71. The energization of thewinding 20 and deenergization of the winding 19 thus causes theindicator 28 to advise the vehicle operator of the most importantmalfunction, i.e., low oil pressure, immediately regardless of othermalfunctions which may exist in the vehicle. 7

In FIG. 6 the single priority control circuit 44 of FIG. 5 has beenmodified to give equal priority to each of two conditions through theaddition of a resistor 78 and a pair of steering diodes 80 and 82 andthe deletion of the transistor 70 and the resistor 74. In FIG. 6 closureof the switches 51 or 53 causes the indicator 28 to provide the sameindication as in the embodiment of FIG. 5 through energization of thecorresponding windings 19 or 21. That is, upon closure of the switch 51the emitter of the transistor 71 is grounded while a voltage is appliedto the base of the transistor 71 through a current path from thejunction 60 which includes the winding 18, the resistor 78, and thediode 80. Though the current thus applied to the base of the transistor71 is sufficient to turn on the transistor 71 it is insufficient toenergize the winding 18 and the resultant magnetic field generated isthus substantially produced by the energization of the winding 19 whenthe transistor 71 becomes conductive. Similarly, upon closure of theswitch 53 the emitter of the transistor 72 is grounded while the base ofthe transistor 72 is provided sufiicient current through the winding 18,the resistor 78, the diode 80, and the resistor 76 to turn on thetransistor 72 and effect energization of the winding 21.

However, if the switch 52 is closed it grounds the winding 20, causingthe winding 20 to become energized. In addition, the closed switch 52grounds the bases of the transistors 71 and 72 through the diode 82.Since the transistors 71 and 72 cannot be conductive when their basesare grounded retransistors 71 and 72 are thus held nonconductivewhenever the switch 52 is closed.

Similarly, closure of the switch 50 grounds the winding 18 so as toeffect energization of the winding 18. Since the switch 50 also groundsthe resistor 78 the supply of base current to the transistors 71 and 72is interrupted so long as the switch 50 is closed. Accordingly, closureof the switch 50 will also prevent energization of the windings 19 and21 while energizing the winding 18.

The control circuit 44 thus provides equal priority to indicatingchanges in the conditions being monitored which effeet closure of theswitches 50 and 52. While persons versed in the art will appreciate thatsome minute currents pass through the winding 18 when one of theswitches 51, 52, or 53 are closed it should be emphasized that properselection of the resistor 78 reduces these currents to a valuesufficiently low as to be of negligible effect on the operation of theindicator 28.

It is thus apparent that the aforedescribed apparatus is not onlycapable of monitoring several conditions by using a single air coregauge but also is able to attach greater priority to certain of theconditions than to the other conditions, though persons versed in theart will appreciate that many modifications of this apparatus inaddition to those herein described may be made without departing fromthe spirit of this invention;

What is claimed is:

1. Apparatus for indicating the status of a plurality of conditionscomprising, in combination, a plurality of detection networks eachincluding a normally open switch that is responsive to at least one ofthe conditions being monitored and a winding connected in series circuitwith the normally open switch, each of the windings being effective whenenergized to generate a magnetic field along its axis, the axes of thewindings being disposed at predetermined angles to each other, at leastone of the detection networks also including a controlled switch in theseries circuit with the normally open switch and the winding in thedetection network, the controlled switch being responsive to thenormally open switch in another detection network whereby the controlledswitch prevents the energization of the winding in series circuittherewith when the normally open switch in the other detection networkis closed and permits energization of the winding in series circuittherewith when the normally open switch in the other detection networkis open, means for connecting the detection networks to a power sourceefiective to energize one of the windings when the normally open switchin series circuit therewith is closed, thereby generating the magneticfield along its axis, and means responsive to the orientation of themagnetic field for indicating which of the conditions being monitoredhas changed sufficiently to close one of the normally open switches.

2. Apparatus for indicating the status of a plurality of conditionscomprising, in combination, a plurality of detection networks eachincluding a normally open switch that is responsive to one of theconditions being monitored for detecting changes in the monitoredcondition, each of the switches being closed upon a predetermined changein the condition being monitored by the switch, and a winding connectedin series with the switch and effective when energized to produce amagnetic field along the axis of the winding, the axes of the windingsbeing aligned at predetermined angles to each other; a controlled switchin series circuit with at least one of the detection networks andresponsive to closure of the switch in one of the other detectionnetworks so as to be conductive when the switch in the other detectionnetwork is open and nonconductive when the switch in the other detectionnetwork is closed; means for connecting the detection networks to apower source efiective upon closure of a normally open switch to causethe energization by the power source of the winding in series circuitwith the normally open switch, closure of each of the normally openswitches which control a controlled switch also preventing energizationof the windings in series circuit with the controlled switches byrendering the controlled switches nonconductive, thereby establishingpriorities between the conditions being monitored; and indicating meansfor indicating the status of the conditions being monitored, theindicating means including an indicia bearing member, means for movingthe indicia bearing member past a certain position in accordance withthe magnetic field produced by the energization of one of the windings,a lamp for illuminating the indicia at the certain position, and meansresponsive to the energization of the windings effective to energize thelamp when a winding is energized and deenergize the lamp when thewindings are deenergized whereby a change in the status of a certainconditipn beirfi monitored effects illumination of predetermined indiciaat e certain position.

3. Apparatus for indicating the status of a plurality of conditionscomprising, in combination, a plurality of detection networks eachincluding a switch for monitoring at least one of the conditions beingmonitored, each of the switches normally being in a first operativestate and being changed to a second operative state upon a predeterminedchange in the condition being monitored by the switch, and a windingconnected in series with the switch and effective when energized toproduce a magnetic field along the axis of the winding, the axes of thewindings being aligned at predetermined angles to each other, at leastone of the detection networks also including a transistor in series withthe winding and the switch, the control terminal of the transistor beingconnected to the switch in another detection network so as to bias thetransistor to its conductive condition when the switch in said otherdetection network is in the first operative state and to itsnonconductive condition when the switch in said other detection networkis in the second operative state, thereby preventing energization of thewinding in series with the transistor when the switch in said otherdetection network is in the second operative state while permitting theenergization of the winding when the switch is in the first operativestate, means for connecting the detection networks to a power source forefi'ecting energization of the windings by the power source in responseto placement of the switches in the second operative state, andindicating means for indicating the status of the conditions beingmonitored, the indicating means including an indicia bearing member,means for moving the indicia bearing member past a certain position inaccordance with the magnetic field produced by the energization of oneof the windings, a lamp for illuminating the indicia at the certainposition, and means responsive to the energization of the windingseffective to energize the lamp when a winding is energized anddeenergize the lamp when the windings are deenergized whereby a changein the status of a certain condition being monitored effectsillumination of predetermined indicia at the certain position inaccordance with the priority of conditions being monitored.

1. Apparatus for indicating the status of a plurality of conditionscomprising, in combination, a plurality of detection networks eachincluding a normally open switch that is responsive to at least one ofthe conditions being monitored and a winding connected in series circuitwith the normally open switch, each of the windings being effective whenenergized to generate a magnetic field along its axis, the axes of thewindings being disposed at predetermined angles to each other, at leastone of the detection networks also including a controlled switch in theseries circuit with the normally open switch and the winding in thedetection network, the controlled switch being responsive to thenormally open switch in another detection netwoRk whereby the controlledswitch prevents the energization of the winding in series circuittherewith when the normally open switch in the other detection networkis closed and permits energization of the winding in series circuittherewith when the normally open switch in the other detection networkis open, means for connecting the detection networks to a power sourceeffective to energize one of the windings when the normally open switchin series circuit therewith is closed, thereby generating the magneticfield along its axis, and means responsive to the orientation of themagnetic field for indicating which of the conditions being monitoredhas changed sufficiently to close one of the normally open switches. 2.Apparatus for indicating the status of a plurality of conditionscomprising, in combination, a plurality of detection networks eachincluding a normally open switch that is responsive to one of theconditions being monitored for detecting changes in the monitoredcondition, each of the switches being closed upon a predetermined changein the condition being monitored by the switch, and a winding connectedin series with the switch and effective when energized to produce amagnetic field along the axis of the winding, the axes of the windingsbeing aligned at predetermined angles to each other; a controlled switchin series circuit with at least one of the detection networks andresponsive to closure of the switch in one of the other detectionnetworks so as to be conductive when the switch in the other detectionnetwork is open and nonconductive when the switch in the other detectionnetwork is closed; means for connecting the detection networks to apower source effective upon closure of a normally open switch to causethe energization by the power source of the winding in series circuitwith the normally open switch, closure of each of the normally openswitches which control a controlled switch also preventing energizationof the windings in series circuit with the controlled switches byrendering the controlled switches nonconductive, thereby establishingpriorities between the conditions being monitored; and indicating meansfor indicating the status of the conditions being monitored, theindicating means including an indicia bearing member, means for movingthe indicia bearing member past a certain position in accordance withthe magnetic field produced by the energization of one of the windings,a lamp for illuminating the indicia at the certain position, and meansresponsive to the energization of the windings effective to energize thelamp when a winding is energized and deenergize the lamp when thewindings are deenergized whereby a change in the status of a certaincondition being monitored effects illumination of predetermined indiciaat the certain position.
 3. Apparatus for indicating the status of aplurality of conditions comprising, in combination, a plurality ofdetection networks each including a switch for monitoring at least oneof the conditions being monitored, each of the switches normally beingin a first operative state and being changed to a second operative stateupon a predetermined change in the condition being monitored by theswitch, and a winding connected in series with the switch and effectivewhen energized to produce a magnetic field along the axis of thewinding, the axes of the windings being aligned at predetermined anglesto each other, at least one of the detection networks also including atransistor in series with the winding and the switch, the controlterminal of the transistor being connected to the switch in anotherdetection network so as to bias the transistor to its conductivecondition when the switch in said other detection network is in thefirst operative state and to its nonconductive condition when the switchin said other detection network is in the second operative state,thereby preventing energization of the winding in series with thetransistor when the switch in said other detection network is in theSecond operative state while permitting the energization of the windingwhen the switch is in the first operative state, means for connectingthe detection networks to a power source for effecting energization ofthe windings by the power source in response to placement of theswitches in the second operative state, and indicating means forindicating the status of the conditions being monitored, the indicatingmeans including an indicia bearing member, means for moving the indiciabearing member past a certain position in accordance with the magneticfield produced by the energization of one of the windings, a lamp forilluminating the indicia at the certain position, and means responsiveto the energization of the windings effective to energize the lamp whena winding is energized and deenergize the lamp when the windings aredeenergized whereby a change in the status of a certain condition beingmonitored effects illumination of predetermined indicia at the certainposition in accordance with the priority of conditions being monitored.